An integrated control system for a vehicle, comprising:
- a friction coefficient calculation unit configured to calculate a friction coefficient of a left side road surface and a right side road surface, respectively, on which a left side wheel and a right side wheel are grounded in a road surface based on vehicle wheel state information and a predetermined setting information collected from the vehicle upon anti-lock brake system (ABS) operation;
- a feedforward braking pressure calculation unit configured to calculate a feedforward braking pressure of each vehicle wheel using the calculated friction coefficients of the left side road surface and the right side road surface;
- an ABS braking pressure calculation unit configured to calculate an ABS braking pressure of the each vehicle wheel based on the calculated feedforward braking pressure and information of the vehicle wheel;
- a rear wheel steering control amount calculation unit configured to calculate a rear wheel steering control amount for yaw compensation using the calculated ABS braking pressure of each vehicle wheel;
- and
- a rear wheel steering controller configured to perform a rear wheel steering control of the vehicle based on the calculated rear wheel steering control amount,
- wherein the feed forward braking pressure calculation unit is configured to calculate a limit braking pressure using the calculated friction coefficient, and add or subtract the braking pressure for compensating a slip rate of each vehicle wheel within the calculated limit braking pressure to mitigate chattering,
- wherein the friction coefficient calculation unit includes a friction coefficient convergence section configured to calculate the friction coefficient of the left side road surface and the right side road surface using the longitudinal force based left side road surface friction coefficient, the longitudinal force based right side road surface friction coefficient, and the lateral force based on the calculated road surface friction coefficient, and
- wherein the friction coefficient convergence section is configured to:
- calculate the current friction coefficient of the left side road surface and the current friction coefficient of the right side road surface using the longitudinal force based left side road surface friction coefficient, the longitudinal force based right side road surface friction coefficient, the lateral force based road surface friction coefficient, the weighting factors, and the friction coefficient determined in the previous control cycle using the following E1 and E2,
- μFL(k)=wLat_FLμLat+wLong_FLμLong_FL+(1−wLat_FL−wLong_FL)μFL(k−1) E1
- μFR(k)=wLat_FRμLat+wLong_FRμLong_FR+(1−wLat_FR−wLong_FR)μFR(k−1) E2
- wherein, μFL(k) refers to the current friction coefficient of the left side road surface, μFR(k) to the current friction coefficient of the right side road surface, μFL(k−1) to the friction coefficient of the left side road surface determined in the previous control cycle, μFR(k−1) to the friction coefficient of the right side road surface determined in the previous control cycle, wLat_FL to the left side wheel lateral weighting factor, μLat to the lateral force based road surface friction coefficient, wLong_FL to the left side wheel longitudinal weighting factor, μLong_FL to the longitudinal force based left side road surface friction coefficient, wLat_FR to the right side wheel lateral weighting factor, wLong_FR to the right side wheel longitudinal weighting factor, and μLong_FR to the longitudinal force based right side road surface friction coefficient.